Add comments

lib/src/widgets/raw_editor.dart

@@ -299,6 +299,12 @@ class RawEditorState extends EditorState
     );
 
     if (widget.scrollable) {
+      /// Since [SingleChildScrollView] does not implement
+      /// `computeDistanceToActualBaseline` it prevents the editor from
+      /// providing its baseline metrics. To address this issue we wrap
+      /// the scroll view with [BaselineProxy] which mimics the editor's
+      /// baseline.
+      // This implies that the first line has no styles applied to it.
       final baselinePadding =
           EdgeInsets.only(top: _styles!.paragraph!.verticalSpacing.item1);
       child = BaselineProxy(